BibHarvest: add custom name to BibUpload tasks
BibHarvest: add custom name to BibUpload tasks

* Use the custom name 'oai' for BibUpload tasks spawned from
  post-harvest processeses, in order to work-around an issue
  with other BibUpload tasks submitted during harvest getting
  equal priority.

tiborsimko/invenio,inveniosoftware/invenio,tiborsimko/invenio,inveniosoftware/invenio